

	As of December 31,
	2018			2019
Land	$	67		$	76
Building and site improvements	93			40
Leasehold improvements	315			382
Computer equipment	858			927
Leased computer equipment	288			539
Leased vehicles	34			24
Internal-use software	51			127
Furniture and fixtures	39			49
Dockless e-bikes	10			78
Construction in progress	832			863
Total	2,587			3,105
Less: Accumulated depreciation and amortization	(946		)	(1,374		)
Property and equipment, net	$	1,641		$	1,731

The Company capitalized $14 million and $76 million in internal-use software costs during the years ended December 31, 2018 and 2019, respectively, which is included in property and equipment, net on the consolidated balance sheets. Amortization of capitalized software development costs was $14 million, $12 million, and $22 million for the years ended December 31, 2017, 2018 and 2019, respectively.

Amounts in construction in progress represent buildings, leasehold improvements, assets under construction, and other assets not placed in service, and build-to-suit leases prior to the adoption of ASC 842 on January 1, 2019. Upon adoption of ASC 842, the Company derecognized build-to-suit assets from construction in progress. Refer to Note 1 - Description of Business and Summary of Significant Accounting Policies for further information.

Depreciation expense relating to property and equipment was $490 million, $399 million, and $433 million for the years ended December 31, 2017, 2018 and 2019, respectively. Included in these amounts were depreciation expense for leased computer equipment in the amount of $26 million, $75 million, and $146 million for the years ended December 31, 2017, 2018 and 2019, respectively. Accumulated depreciation and amortization included $101 million and $247 million of leased computer equipment depreciation as of December 31, 2018 and 2019, respectively.

In October 2017, the Company sold real estate in the United States resulting in net sales proceeds of $175 million, inclusive of a loss on sale of $79 million.